// 笔试强训：爱丽丝的人偶

#include <iostream>
using namespace std;

int main() {
    int n = 0; cin >> n;
    int left = 1, right = n;
    while(left <= right)
    {
        cout << left << " ";
        left++;
        if(left <= right)
            cout << right << " ";
        right--;
    }
    return 0;
}